<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
          margin: 0;
          padding: 0;
        }
    
        .box {
          width: 500px;
          height: 320px;
          display: flex;
          flex-direction: column;
          margin: 50px auto;
          border: 3px solid #333;
        }
    
        .box > ul {
          height: 60px;
          display: flex;
        }
    
        .box > ul > li {
          flex: 1;
          display: flex;
          justify-content: center;
          align-items: center;
          font-size: 30px;
          color: #fff;
          background-color: skyblue;
          cursor: pointer;
        }
    
        .box > ul > li.active {
          background-color: orange;
        }
    
        .box > ol {
          flex: 1;
          position: relative;
        }
    
        .box > ol > li {
          width: 100%;
          height: 100%;
          background-color: purple;
          font-size: 50px;
          color: #fff;
          position: absolute;
          left: 0;
          top: 0;
          display: none;
        }
    
        .box > ol > li.active {
          display: block;
        }
      </style>
    <script src='./tab3.js'></script>
</head>
<body>
    <div class="box" id="box2">
        <ul>
          <li class="active">1</li>
          <li>2</li>
          <li>3</li>
          <li>4</li>
        </ul>
        <ol>
          <li class="active">1</li>
          <li>2</li>
          <li>3</li>
          <li>4</li>
        </ol>
      </div>
    <script>
        var t1 = new MyTab('#box2');

    </script>
</body>

</html>